Forced draft unit for oil burners



2 Sheets-Sheet 1 Ine/enfans" Jwms" j, rfe'e .57u66 lz/ffr J. 1'.. BREESE ETAL I FORCED DRAFT UNIT FOR OIL BURNERS Filed oct. 21, 1939 Aug. 8, 1944.

ATTORNEYS.v

Aug. vs, 1944.v

J. L. BRE'ESE ETAL FORCED DRAFT UNIT FOR OIL BURNERS Filed Oct. 21. 1939 2 Sheets-Sheet 2 Jkye?? faro' Ja/fmsz/eewe ATTORNEYS Patented Aug. 8, 1944` UNITED STATES PATENT OFFICE FORCED DRAFT UNrr For: on. BUaNEas James L. Breese and Bruce Hayter, Santa Fe, N. Mex., assignors toOil Devices, Santa Fe,

N. Mex., a limited partnership of Illinois Application October 21, 1939, Serial No. 300,593

7 Claims. (Cl. 158-91) Our invention relates to an improvement in oil burners and has for one purpose to provide a simple and inexpensive forced draft unit .in which means for forcing a circulation of air are associated with a burner. herein shown as applied to a pot type burner.

Another purpose is the provision of means for cooling or preventing the heating of a fan motor, while maintaining it in operating proximity to an oil burner.

Another purpose is the provision of improved mounting means for fan and motor.

Other purposes will appear from time to time in the course of the specification and claims.

We illustrate our invention ,more or less dlagrammatically in the accompanying drawings wherein:

Fig. l is a side elevation with parts in section; Fig. 2 is a vertical section on an enlarged scale; Fig. 3-is a section on the line 3-3 of Fig. l on an enlarged scale; and

Fig. 4 is a section on the line 4-4 of Fig. 1 on an enlarged scale. Like parts are indicated by like symbols throughout `the specification and` drawings.

Referring to the drawings, I indicates an outer .drum or housing provided with bottom air inlet apertures 2. 3 indicates an angle ring extendingaround the interior of the drum I and adapted to receive a supporting flange 4 of the inner drum 5. Positionedwithin the inner drum is the pot 5, herein shown as provided with a plurality of air inlet apertures 1 arranged in a Our invention is '.vide a motor housing including a top plate 25 and a housing box 29 secured thereto, as by rivets 21 or by any other suitable securing' means. Mounted within the box 25 is a. motor 28, the details of which do not of themselves form part of the present' invention. A motor shaft 29 extends upwardly through an oiset of the plate 25, which is aligned with and extends upwardly into the aperture 3I in the disc I3.

' Mounted upon the motor shaft 29 is any suitable hub 32, carrying a fan'body 33 having generally flat radial plates 34 having upwardly extending fianges or fan vanes 35. This fan structure extends upwardly into and conforms generally to the aperture I2, with the vanes 35 ex tending above the level of the bottom II.

If desired, we mayemploy fixed air distributor members 39, outwardlyextending from the upper surface of the bottom plate I I. We may employ any suitable means for supporting the motor housing, but we illustrate for example blocks of yielding compressible material 31 ot rubber or plurality of horizontal rows. Any suitable means may be employed for supplying secondary air, but we illustrate a top row 8 of secondary air inlet apertures, which are shownas larger and more closely spaced than theapertures 1.

The pot 6 is illustrated as having a top ange Iwith a circumferential downward edge I9 seating upon and conforming closely to the upper edge of the drum 5 and forming .a substantially air tight closure therewith.

The drum 5 has any suitable bottom member II, provided with a. central axial aperture I2. Herein shown as secured to the bottom member Il is a bottom disc I3 having an upwardly extending circumferential ilange I4 and a further outward extension or ring I5, which conforms to and maybe secured to the bottom II, as' by a plurality of headed studs I6 extending downwardly from the vbottom II and seating in slots Il in the ring or flange I5. Each of these slots terminates in an enlarged aperture-l9, whereby, upon slight rotation of the plate I3, the plate the like, through which may pass securing screws 33, the lower ends of which penetrate outer portions oi' the plate 25. 39 is any suitable lubricating inlet for the box 29, which may be closed for example by the cap 40, available for easy lubrication.

4I is a fuel line lextending to the bottom of the pot 9. Any suitable vvalve'-\means 42 may be employed for controlling thevolume of flow of the liquid fuel. 43 is any suitable conduit adapted to carry conductors 44, which pass integrally through an elbow 45 for yconnection tothe motor 23." It will be observed that the fuel line 4I and the conduit 43l pass inwardly through the drum I through appropriate apertures.

It will be realized that whereas we have described and illustrated a practical and operative device, nevertheless many changes may be made in the size, shape, number and dispositionof parts without departing from the spirit of ou'r invention. We therefore wish our description and drawings to be taken as in a broad sense illustrative or diagrammatic, rather than as limiting us to our precise showing.

'I'he use and operation of our invention are as follows:

Under some circumstances we find it advantageous to provide a simple and inexpensive `forced draft unit, herein shown as applied to a.

pot type burner. Such forced draft means are advantageous. for example, for ranges and for hot water heaters. We therefore provide a small To avoidany possibility of the unit coming loose, we may employ a screw 50 passing through a clip 5l, which in turn may be secured to the ring l5.

Air distrlbutorsor fixed vanes 38 are effective to remove the swirl of the air occasioned by the employment of the fan without a surrounding housing. It is important that the air enter radlally rather than tangentially in order not to destroy the balance of combustion, and the vanes 35 as shown have this effect. 'I'he flow of air inwardly through the apertures 20 and up through the fan serves as a cooling or protective medium interposed between the motor and the burner. The air which moves rapidly inwardly through the apertures 20, upwardly through the fan, and outwardly across the bottom of the 4pot 6, prevents any tendency of the motor to heat. Since the motor runs in a permanent bath of oil, it

will operate with a minimum of attention or inspection. The rubber mounting removes all traces of vibration.

A very small motor can be employed, and the power consumption of the unit is so low that it may, if desired, be continuouslyoperated.

lrounding said pot and having a bottom with an air inlet aperture .vertically aligned with the center of the pot bottom, vand a forced draft unit including a plate, a motor on said plate, a motor ,shaft mounted for rotation about a generally vertical axis and a fan mounted on said motor shaft, means for supporting s aid plate'below and spaced downwardly from. the bottom of said housing, with the axis of said fan aligned with the center of the aperture in said bottom am` with the central axis of the pot, said fan comprising vanes extending upwardly from the plane of said Vhousing bottom and located radially substantially within the periphery of said pot, air being free to flow into the space between said plate and the bottom of the housing, and means located between the pot bottom and the bottom of the housing and in the space defined therebetween for causing a radial delivery of the air delivered by'said vanes, including a plurality of fixed vanes mounted on. and upwardly extending from the 'bottom of the housing, and locatedin the direct line of delivery of air from the fan vanes, and terminating at their outer edges adja'- cent the periphery of the pot, said fixed vanes including generally radial inner portions and being curved laterally toward their outer deliv' ery edges, whereby a substantially circumferential movement is imparted to the air delivered thereby.

2. In combination, a burner pot having vair apertures at a plurality of levels in the side wall thereof, means for delivering a liquid fuel to the interior of the pot, andmeans for delivering air under pressure to the space aboutthe exterior of said pot, including an air tight housing surrounding said p ot and having a bottom with an air inlet aperture vertically aligned with the center of the pot bottom, and a forced draft unit including a motor, a fan mounted for rotation about a generally vertical axis, the axis of said fan aligned with the center of the aperture in said bottom and with the central axis of the pot, said fan having vanes extending upwardly from the plane of said housing bottom and located radially substantially within the periphery of said Pot, and means located between the pot bottom and the bottom of the housing and in the space defined therebetween for causing a radial delivery of the air delivered by said vanes, including a plurality of fixed vanes mounted on and upwardly extending from the bottom of the housing, and located in the direct line of delivery of air from the fan vanes, and terminating at their outer edges adjacentthe periphery of the pot, said fixed vanes including generally radial inner portions and being curved laterally toward their outer delivery edges, whereby a substantially circumferential movement is imparted to the air delivered thereby.

3. In a heater, a burner pot having air apertures located at a plurality of levels in its side wall, means for delivering a liquid fuel to the interior of the pot, a substantiallyair tight housing surrounding and closely adjacent said pot and extending upwardly vabout said pot, said housing having a bottom portion, said bottom portionv having a generally circular aperture in line with the central axis of the pot, the bottom portion being spaced slightly below the bottom of the Dot, and means for delivering air under pressure to the space between the housing and the pot, including a motor and fan assembly removable as a unit from the heater, thefan being coaxial with the central axis of the pot, said ianl extending through said aperture in the bottom of the housing and having a plurality of vanes located in the space between the bottom of the pot and the bottom of the housing, and of a 'radius less than the radius of said aperture, and means for securing said motor and fan readily removably upon the bottom of said housing, including opposed interpenetrating ele- 1 ments 'actuatable from below the bottom of the housing, whereby the motor and fan may readily be applied to or removed from 'the bottom of the housing, without the necessity of access to the interior of the housing.

4. In a heater, a burner pot having a cylindrical side wall and having airv apertures located at a pluraiity of levels in said side wall, means for delivering a liquid fuel to the interior of the of the air, said vanes pot, a substantially air tight housing surrounding and closely adjacent said pot and extending upwardly about said pot, said housing having a bottom portion, said bottom portion having a generally circular aperture in line with the central axis of the pot, the bottom portion being spaced slightly below the bottom of the pot, and means for delivering air'under pressure to vthe space between the housing and the pot including a fan and means for rotating it, the fan being generally co-axial with the pot and having fan vanes located in the space .between the bottom of the pot and the bottom oi' the housing, the fan being of the centrifugal type and being adapted to deliver air outwardly across the bottom ofthe pot and toward the periphery of said pot bottom'and xed vanes, located in the space betweenthe bottom of the pot and the housing, for controlling the movement of the air said vanes mounted on the inner face of the bottom portion of said surrounding housing and out of contact with said pot.

5. In a heater, a burner pot having an open end, a closed end, and a generally cylindrical side wall, saidside wall having air inlet apertures located at a plurality of distances from the ends of the pot, means for delivering a liquid fuel to the interior of the pot, a substantially air tight housing surrounding and closely adjacent said pot,y said housing having an end portion said end portion having a generally circular aperture in line with the central axis of the pot, said end portion being spaced slightly away from the closed end of the pot. and meansfor delivering air under.pressure to the space between the housing and the pot, including a fan and means for rotating it, the fan being generally co-axiaLwith the pot and having fan vanes located in the space between the end of the pot and the end portion of the housing, the fan being of the centrifugal type and being adapted to deliver air generally radially outwardly across the end of the pot and toward the periphery of the end of the pot, and fixed vanes located in the space between the end of the pot and the end of the housing, for controlling the movement c being mounted on the inner face of the end of said housing and out of contact with said pot.

6. In a heater. a burner pot having an open end, a closed end, and side wall, said side wall a generally cylindrical' having air inlet apertures located at a plurality of distances from lthe ends of the pot, means fordelivering a liquid fuel to the interior of the pot, a substantially air tight housing surrounding and closely adjacent said pot, said housing having an end portion, said end portion having a generally "circular aperture in line with the central axis of the pot, said end portion being spaced slightly away from the closed end of the pot,J and means for delivering air under pressure to the space between the housing and the pot, including a fan and means for rotating it, the fan being generally oo -axial with the pot and having fan vanes located in the space between the end of the pot and the end portion of the housing, the fan being of the centrifugal type and-.being adapted to `de-` liver air generally radiaily outwardly across the end of the pot and toward the periphery of the end of the pot, and means located in" the space between the endl` of the pot andthe end of the housing, for controlling the movement of the air as it flows outwardly from the fan.

'1. In a heater, a burner pot having an Iopen end, a closed end, and a generally cylindrical side wall, said side wall having air inlet apertures located at a plurality ofedistances from the ends of the pot, means for delivering a liquid fuel to the interior of the pot, a substantially air tight housing surrounding and closely adjacent said pot, said housing having an end portion, said end portion having a generally circular aperture in line with the central axis of the pot,

said end portion being spaced slightly away from the closed end of the pot, and means for delivering air under pressure to the space between the housing and the pot, including a fan and means for rotating it, the fan being generally o-axial with the pot and having fan vanes located in the space between the end of the pot and the end -portion of the housing, the fan being of the centrifugal type and being adapted to deliver air generally radially outwardly across the end of the pot and toward the periphery of the end of the pot, and means located in the space between the end of the pot and the end of the housing, for controlling the movement of the air as 4it flows outwardly from the fan, said means including vanes xed in relation to said pot and housing.

JAMES L BREEsE. BRUCE Harm. 

